The Reproductive Poicers of Domesticated Animals. 265 



most irregular intervals. This results from one of the following 

 causes : either the female does not become impregnated, or else 

 the embryo is imperfectly developed. The non-impregnation of 

 the female may generally be traced to an excessive fatness in one 

 or both of the animals, and an absence of constitutional vigour. 

 The breeding powers are most energetic when the animals are in 

 moderate condition, uninfluenced either by extreme fatness or 

 leanness. The impregnation of the female is in some cases pre- 

 vented by natural defect or malformation ; but I am strongly 

 inclined to believe that such cases are comparatively rare. 



Many animals are condemned as barren which are only 

 temporarily so, in consequence of injudicious feeding and 

 management, or relatively so, in consequence of the male 

 being unsuited, from too close proximity of blood, or from both 

 animals being deficient in constitutional vigour. Examples of 

 each of these cases are frequent. Some very well-bred heifers 

 which had been condemned as barren, because, after very 

 persevering trials with various bulls, they failed to breed, I 

 placed for four Or fi^ve months upon poor hilly pastures, 

 to bring them down in condition, and immediately after this 

 they bred without difficulty. Captain J. T. Davy has com- 

 municated to me some similar instances in which most hopeless 

 cases of barrenness were overcome by turning the heifers upon 

 poor common land with a young bull. He states that in other 

 cases the same result has been attained by working the heifers in 

 the plough, like oxen, after which there has been no trouble 

 in getting them to breed. I am also informed by Mr. Strafford 

 of another instance in which apparent sterility has been success- 

 fully overcome. The late Mr. Jonas Webb purchased a valuable 

 cow from the herd of the late Lord Spencer for a moderate sum 

 of money, in consequence of her being condemned as barren. 

 After the purchase she was driven from Wiseton to Babraham, a 

 distance of between 100 and 120 miles, and within a short 

 time she bred. ' Dodona,' the cow in question, when a 

 heifer, produced twin-calves, and subsequently she produced 

 another calf, but, as she then ceased to breed, she was sold. A 

 change of climate, however, brought her again into breeding 

 condition, and at the time of her decease no less than 160 

 valuable animals could be traced to this cow, which had been 

 sold on two occasions as barren. Mr. Webb had an almost 

 parallel case in 'Cella,' which, under somewhat similar treatment, 

 after being condemned as barren, had a progeny of over 180 traced 

 to her at the time of her death. These results were all gained by 

 somewhat severe treatment, whereby unhealthy accumulations of 

 fatty matter, previously existing in the body and impeding 

 generation, were taken up into the system for the support of life. 



